Description.
The circuit shown here is of a simple 0 to 9 display that can be employed in a lot of applications. The circuit is based on asynchronous decade counter 7490(IC2), a 7 segment display (D1), and a seven segment decoder/driver IC 7446 (IC1).
The seven segment display consists of 7 LEDs labelled ‘a’ through ‘g’. By forward biasing different LEDs, we can display the digits 0 through 9. Seven segment displays are of two types, common cathode and common anode. In common anode type anodes of all the seven LEDs are tied together, while in common cathode type all cathodes are tied together. The seven segment display used here is a common anode type .Resistor R1 to R7 are current limiting resistors. IC 7446 is a decoder/driver IC used to drive the seven segment display.
Working of this circuit is very simple. For every clock pulse the BCD output of the IC2 (7490) will advance by one bit. The IC1 (7446) will decode this BCD output to corresponding the seven segment form and will drive the display to indicate the corresponding digit.

Sir , can i ask something what that you use ? CD7448 or SN7448 ? SN74ls48 ? sorry for this question i didnt read all the comment below . i just read the description and theres no detail about what ic has been used. Please answer me ,thank in advance 🙂

for each pulse input the counter will advance by one. that is the indication will advance 0,1,2,3….9 for each pulse in. use the carry over of 7490 to next (10s) counter then it will read from 00 to 99. The application is unlimited. Say number of people passing a check post, no of bottles or any item passing through a conveyor etc, by using suitable sensor like micro switch, optical or proximity sensor etc.

hello for each pulse input the counter will advance by one. that is the indication will advance 0,1,2,3….9 for each pulse in. use the carry over of 7490 to next (10s) counter then it will read from 00 to 99. The application is unlimited. Say number of people passing a check post, no of bottles or any item passing through a conveyor etc, by using suitable sensor like micro switch, optical or proximity sensor etc.

Well, you can use. But remember as you keep increasing the resistor value the brightness of the display keeps decreasing. And yes, decreasing the resistor value below 220R will increase the brightness but will also damage the display. Hope you get this. BTW, read some good basic electronics.

fyi, i had put a switch to make the display stay at 9 and it’s succesful but what other components that i can use to replaced the switch? can we use gates? and if yes, how should i place it? i want it to stop and stay at 9 automatically. please help me. i wanna know this really bad. thank you sir. have a nice day 🙂

Hi Priyank input pulse is given to Pin14 of the IC to count. each pulse it will move to next number in ascending order. You can use apush to on switch connect between 5volt and Pin14. for each push the number will advance.

Sir a have a few questions to ask and i need you to answer my questions immediately please coz tomorrow i’ll be defending my project and one of the circuits that i used there is your design,here are my questions:
1.Why is it that you didn’t use a encoder?usually there is an encoder before the decoder.
2.How did you compute the values of the resistor?
3.What is the use of the asynchoronous decade counter?Does it really need to be asynchronous?
4.What should be the clock that i will use here?can i use a 555 astable multivibrator circuit to provide the BCD input??

PLEASE REPLY..THANK YOU VERY MUCH SIR and to anyone who can help me..THANKS!

can u help provide some circiuits that would displayed 0-9
with just a push botton.say e.g. ill presh #4 button and the led will automatically display (4)or else the #3 button and it also displayed (3) i really need it asap.plsssssss

hi guys., pls help me,.i want to build an up and down counter using 1 digit seven segment display,.can somebody sends me a circuit that counts from 0-9 then will reverse. and the switch to be used is a sensor,.

Hi you guys. What I’m wondering is how to get the 7490 to reset to 1 instead of 0. I got two 7-segment displays that reset to zero after they reach 12. Another group is trying to get their two 7-segment displays to reset after 60.

Hi Vasanth each positive going pulse to the input pin 14 will add 1 to indicated number. say if it was at 4 with one positive going input pulse it will change to 5 it will count up to 9 and reset back to zero.
you can simply produce pulse through a 10k resistance connected bet ween positive and pin 14 of the IC through bell push switch. each push will add one to the displayed digit.